Recipe for a creamy sauce/salmon and mashed potatoes?

Mashed Potatoes

You could do a creamy sauce..

Google Buerre Blanc

Bechemel, or Cream Sauce.

I prefer to have fish with smashed potatoes, risotto, rice, other grains... (barley, quinoa, etc.)

Because... fish is really delicate in texture as is mash. Also add some crispy veg (I love sauteed rapini/fiddleheads)

Also, white wine, lemon and delicate herbs (dill, chives, parsley, basil, tarragon) all would go well

Hollandaise is fine but I'm not a fan of it. Why not try looking up... Savoury Sabayon for fish or something!

Get creative, your options are endless.

Sure, you COULD go with a cream (or it is spelled creme? I can NEVER remember...) sauce from scratch, but I prefer simple condensed cream of celery soup. add a SMALL amount of water to thin as desired, but otherwise, just use the condensed soup as-is. Add some grated or shredded cheese on top, using a mild cheese such as Provolone, Colby, Monterrey Jack, or mozzarella even. Any mild creamy white cheese will do to complement the cream of celery soup. I have used both cream of mushroom and cream of chicken successfully. Otherwise, if you poach the salmon, you will have the liquid from poaching to start with. Make a rue in a small sauce pan by collecting the drippings, adding some all purpose flour and simmer for a few minutes, and then add heavy cream or half and half to thin the rue as desired. It will thicken as it simmers with the cream or half and half. Last, sprinkle with shredded mild cheese and continue to simmer on a low heat until it all melts and thoroughly homogenizes. Stir constantly to avoid lumps or burning the rue. It may not LOOK burned, but if it IS, it will taste like it. It is on the verge of starting to burn when the bubbles from the slow simmer start to go away. Cream sauces are really simple in nature, so you do not really need a specialized recipe for a really basic cream sauce made from mostly flour, meat drippings and some form of cream additive. Add a few volatile herbs such as cilantro or chives and some grated garlic, and away you go... NO salt, but maybe a pinch or two of freshly cracked or ground pepper on top. Use a little parsley as a garnish on the side. Salmon goes well with parsley. I simply love finely chopped chives over mashed potatoes. That and a little real butter, but with a cream sauce, you do not need any butter at all, unless you choose to add some instead of milk to your mashed potatoes. I learned all of this from my mom, who was determined I would be a bachelor forever and would need to know how to cook for myself. She was of the mind that if you are going to cook for yourself, you should at least be good at it... and even better when it comes to feeding others...